The present invention relates to product sampling apparatus, and in particular to sampling apparatus in which extracted samples are directed to selected ones of a plurality of sample collection containers.
Certain product manufacturing operations require that the composition of the product be monitored to obtain representations of what is being generated by the manufacturing process. Monitoring may be accomplished with samplers that take samples of product from a main body of the product. When a composite sample is required, the sampler may be periodically operated over time to withdraw and collect a plurality of discrete samples of product from the main body, which samples are mixed together and represent a composite of the product. If the immediate composition of a product is to be determined, the samples are individually analyzed.
Four exemplary types of known sampling apparatus are disclosed in U.S. Pat. Nos. 4,147,062, 4,262,553, 4,475,410 and 4,744,255, issued to Ben E. Jaeger, the present inventor, and the teachings of all of which are incorporated herein by reference. Samplers of the type disclosed in said patents are attached about an opening to a pipe or vessel that contains product to be sampled. The samplers have a plunger in which is a sample receiving recess, and the plunger and recess are extended through the opening to the vessel to project the recess into the main body of product in the vessel to receive a product sample in the recess. The plunger and its product sample containing recess are then retracted to deliver the product sample to a collection point in the sampler.
When a sampler is operated to obtain discrete product samples and deliver the samples to a collection point, a sample collection container normally is provided at the collection point to receive and hold the samples. Sample collection containers are of limited size and can hold only a finite number of product samples before becoming full, so it is necessary that the sample collection container be attended to from time to time in order to replace full sample collection containers with empty containers. The time interval between replacements depends upon the capacity of the containers, the product sample rate and the volumetric size of the discrete samples delivered to the containers. When the interval is relatively short, replacement of full with empty sample collection containers can be inconvenient, time consuming, require the presence of a person who might be otherwise gainfully occupied, and add unwanted costs to the sampling operation.
Prior efforts to alleviate the problem of having to frequently replace full with empty sample collection containers contemplate using rotary indexing samplers, in which a turntable carries a plurality of sample collection containers in an arcuately spaced circular array. The turntable is rotated to place selected ones of the collection containers in position to receive samples delivered by a sampler, with the use of a plurality of collection containers serving to increase the capacity of the sample collection station and extend the time interval between the need to replace of full with empty containers. A disadvantage to rotary indexing samplers is that because the plurality of collection containers are arranged in a circular array, an operator observing the sample collection station has his view of the remote collection containers obstructed by the near collection containers, much as a person standing alongside a merry-go-round has his view of the far horses blocked by the near horses. In consequence, an operator is not able to readily visually discern whether the remote collection containers are full and require replacement, or if samples delivered to the remote containers have encountered a blockage in the delivery line.